"Other high ranking Republicans are expressing support to Howie, although not quite so openly, for fear of retribution from establishment Republicans," Howie's campaign writes in its release.

He goes on to quote two anonymous supporters giving such compelling endorsements as "You have my vote":

"Private assurances of support continue to come in" Howie said.

"You have my vote," said one prominent Republican.

Another who is unable to endorse in public said, "When I compare Mike Rounds and Gordon Howie based on principle, you have my vote."

Howie says these unnamed backers are evidence of the "silent majority" sympathetic to his candidacy -- a majority he says even polling is entirely unable to "accurately evaluate."

Indeed, ancient lore makes clear that only those pure of heart are able to perceive the silent majority, much like similar mythic creatures as the unicorn.

Look: the point of an endorsement is to get voters to like your campaign by showing that someone else they know and trust supports the candidate. (The Washington Post's Chris Cilizza breaks down different types of endorsements, from most to least influential.) Anonymous endorsements defeat the purpose of an endorsement -- and only make the candidate look desperate and weak. There is absolutely considerable pressure in the Republican Party to close ranks behind Mike Rounds and against Howie -- but when even strong supporters won't do so publicly, it doesn't bode well for Howie's ability to expand his coalition beyond those initial supporters.

What would bode well for that? More endorsements like the one supporter Howie does name: Gary Jerke, who served in the state House from 2005 to 2008. Jerke was appointed by Mike Rounds, which makes his endorsement of Howie over Rounds nice symbolism.